# Cosine (cos) Calculator

### Cosine (cos) Calculator

Calculated cosine() of the number

### cos() function

Cosine is the trigonometric function that is equal to the ratio of the side adjacent to an acute angle (in a right-angled triangle) to the hypotenuse.

This is an online free cos calculator. You can calculate value of cos() trignometric function easily using this tool.

### Important Abbreviations to remember

• SOH: Opposite / Hypotenuse (Sine)
• CAH: Adjacent / Hypotenuse (Cosine)
• TOA: Opposite / Adjacent (Tangent)

### Interactive animation of Sine & Cosine functions

Drag the red dot around to see how it affects the sine and cosine values below.

### Understanding the Main Trigonometric Functions

In mathematics, the trigonometric functions (also called circular functions, angle functions or goniometric functions) are functions of an angle. They relate the angles of a triangle to the lengths of its sides. Degrees and Radians are units of measuring these angles. Degrees originated as an unit to measure how far constellations moved in a day (1 degree ~ 1 day of movement). Degrees measure angles by how far we tilted our heads(Observer's view point). Radians measure angles by distance traveled(Movers's view point).